contrib/serf/buckets/aggregate_buckets.c

   1 /* Copyright 2002-2004 Justin Erenkrantz and Greg Stein
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include "serf.h"
  17 #include "serf_bucket_util.h"
  18
  19
  20 /* Should be an APR_RING? */
  21 typedef struct bucket_list {
  22     serf_bucket_t *bucket;
  23     struct bucket_list *next;
  24 } bucket_list_t;
  25
  26 typedef struct {
  27     bucket_list_t *list; /* active buckets */
  28     bucket_list_t *last; /* last bucket of the list */
  29     bucket_list_t *done; /* we finished reading this; now pending a destroy */
  30
  31     serf_bucket_aggregate_eof_t hold_open;
  32     void *hold_open_baton;
  33
  34     /* Does this bucket own its children? !0 if yes, 0 if not. */
  35     int bucket_owner;
  36 } aggregate_context_t;
  37
  38
  39 static void cleanup_aggregate(aggregate_context_t *ctx,
  40                               serf_bucket_alloc_t *allocator)
  41 {
  42     bucket_list_t *next_list;
  43
  44     /* If we finished reading a bucket during the previous read, then
  45      * we can now toss that bucket.
  46      */
  47     while (ctx->done != NULL) {
  48         next_list = ctx->done->next;
  49
  50         if (ctx->bucket_owner) {
  51             serf_bucket_destroy(ctx->done->bucket);
  52         }
  53         serf_bucket_mem_free(allocator, ctx->done);
  54
  55         ctx->done = next_list;
  56     }
  57 }
  58
  59 void serf_bucket_aggregate_cleanup(
  60     serf_bucket_t *bucket, serf_bucket_alloc_t *allocator)
  61 {
  62     aggregate_context_t *ctx = bucket->data;
  63
  64     cleanup_aggregate(ctx, allocator);
  65 }
  66
  67 static aggregate_context_t *create_aggregate(serf_bucket_alloc_t *allocator)
  68 {
  69     aggregate_context_t *ctx;
  70
  71     ctx = serf_bucket_mem_alloc(allocator, sizeof(*ctx));
  72
  73     ctx->list = NULL;
  74     ctx->last = NULL;
  75     ctx->done = NULL;
  76     ctx->hold_open = NULL;
  77     ctx->hold_open_baton = NULL;
  78     ctx->bucket_owner = 1;
  79
  80     return ctx;
  81 }
  82
  83 serf_bucket_t *serf_bucket_aggregate_create(
  84     serf_bucket_alloc_t *allocator)
  85 {
  86     aggregate_context_t *ctx;
  87
  88     ctx = create_aggregate(allocator);
  89
  90     return serf_bucket_create(&serf_bucket_type_aggregate, allocator, ctx);
  91 }
  92
  93 serf_bucket_t *serf__bucket_stream_create(
  94     serf_bucket_alloc_t *allocator,
  95     serf_bucket_aggregate_eof_t fn,
  96     void *baton)
  97 {
  98     serf_bucket_t *bucket = serf_bucket_aggregate_create(allocator);
  99     aggregate_context_t *ctx = bucket->data;
 100
 101     serf_bucket_aggregate_hold_open(bucket, fn, baton);
 102
 103     ctx->bucket_owner = 0;
 104
 105     return bucket;
 106 }
 107
 108
 109 static void serf_aggregate_destroy_and_data(serf_bucket_t *bucket)
 110 {
 111     aggregate_context_t *ctx = bucket->data;
 112     bucket_list_t *next_ctx;
 113
 114     while (ctx->list) {
 115         if (ctx->bucket_owner) {
 116             serf_bucket_destroy(ctx->list->bucket);
 117         }
 118         next_ctx = ctx->list->next;
 119         serf_bucket_mem_free(bucket->allocator, ctx->list);
 120         ctx->list = next_ctx;
 121     }
 122     cleanup_aggregate(ctx, bucket->allocator);
 123
 124     serf_default_destroy_and_data(bucket);
 125 }
 126
 127 void serf_bucket_aggregate_become(serf_bucket_t *bucket)
 128 {
 129     aggregate_context_t *ctx;
 130
 131     ctx = create_aggregate(bucket->allocator);
 132
 133     bucket->type = &serf_bucket_type_aggregate;
 134     bucket->data = ctx;
 135
 136     /* The allocator remains the same. */
 137 }
 138
 139
 140 void serf_bucket_aggregate_prepend(
 141     serf_bucket_t *aggregate_bucket,
 142     serf_bucket_t *prepend_bucket)
 143 {
 144     aggregate_context_t *ctx = aggregate_bucket->data;
 145     bucket_list_t *new_list;
 146
 147     new_list = serf_bucket_mem_alloc(aggregate_bucket->allocator,
 148                                      sizeof(*new_list));
 149     new_list->bucket = prepend_bucket;
 150     new_list->next = ctx->list;
 151
 152     ctx->list = new_list;
 153 }
 154
 155 void serf_bucket_aggregate_append(
 156     serf_bucket_t *aggregate_bucket,
 157     serf_bucket_t *append_bucket)
 158 {
 159     aggregate_context_t *ctx = aggregate_bucket->data;
 160     bucket_list_t *new_list;
 161
 162     new_list = serf_bucket_mem_alloc(aggregate_bucket->allocator,
 163                                      sizeof(*new_list));
 164     new_list->bucket = append_bucket;
 165     new_list->next = NULL;
 166
 167     /* If we use APR_RING, this is trivial.  So, wait.
 168     new_list->next = ctx->list;
 169     ctx->list = new_list;
 170     */
 171     if (ctx->list == NULL) {
 172         ctx->list = new_list;
 173         ctx->last = new_list;
 174     }
 175     else {
 176         ctx->last->next = new_list;
 177         ctx->last = ctx->last->next;
 178     }
 179 }
 180
 181 void serf_bucket_aggregate_hold_open(serf_bucket_t *aggregate_bucket,
 182                                      serf_bucket_aggregate_eof_t fn,
 183                                      void *baton)
 184 {
 185     aggregate_context_t *ctx = aggregate_bucket->data;
 186     ctx->hold_open = fn;
 187     ctx->hold_open_baton = baton;
 188 }
 189
 190 void serf_bucket_aggregate_prepend_iovec(
 191     serf_bucket_t *aggregate_bucket,
 192     struct iovec *vecs,
 193     int vecs_count)
 194 {
 195     int i;
 196
 197     /* Add in reverse order. */
 198     for (i = vecs_count - 1; i >= 0; i--) {
 199         serf_bucket_t *new_bucket;
 200
 201         new_bucket = serf_bucket_simple_create(vecs[i].iov_base,
 202                                                vecs[i].iov_len,
 203                                                NULL, NULL,
 204                                                aggregate_bucket->allocator);
 205
 206         serf_bucket_aggregate_prepend(aggregate_bucket, new_bucket);
 207
 208     }
 209 }
 210
 211 void serf_bucket_aggregate_append_iovec(
 212     serf_bucket_t *aggregate_bucket,
 213     struct iovec *vecs,
 214     int vecs_count)
 215 {
 216     serf_bucket_t *new_bucket;
 217
 218     new_bucket = serf_bucket_iovec_create(vecs, vecs_count,
 219                                           aggregate_bucket->allocator);
 220
 221     serf_bucket_aggregate_append(aggregate_bucket, new_bucket);
 222 }
 223
 224 static apr_status_t read_aggregate(serf_bucket_t *bucket,
 225                                    apr_size_t requested,
 226                                    int vecs_size, struct iovec *vecs,
 227                                    int *vecs_used)
 228 {
 229     aggregate_context_t *ctx = bucket->data;
 230     int cur_vecs_used;
 231     apr_status_t status;
 232
 233     *vecs_used = 0;
 234
 235     if (!ctx->list) {
 236         if (ctx->hold_open) {
 237             return ctx->hold_open(ctx->hold_open_baton, bucket);
 238         }
 239         else {
 240             return APR_EOF;
 241         }
 242     }
 243
 244     status = APR_SUCCESS;
 245     while (requested) {
 246         serf_bucket_t *head = ctx->list->bucket;
 247
 248         status = serf_bucket_read_iovec(head, requested, vecs_size, vecs,
 249                                         &cur_vecs_used);
 250
 251         if (SERF_BUCKET_READ_ERROR(status))
 252             return status;
 253
 254         /* Add the number of vecs we read to our running total. */
 255         *vecs_used += cur_vecs_used;
 256
 257         if (cur_vecs_used > 0 || status) {
 258             bucket_list_t *next_list;
 259
 260             /* If we got SUCCESS (w/bytes) or EAGAIN, we want to return now
 261              * as it isn't safe to read more without returning to our caller.
 262              */
 263             if (!status || APR_STATUS_IS_EAGAIN(status) || status == SERF_ERROR_WAIT_CONN) {
 264                 return status;
 265             }
 266
 267             /* However, if we read EOF, we can stash this bucket in a
 268              * to-be-freed list and move on to the next bucket.  This ensures
 269              * that the bucket stays alive (so as not to violate our read
 270              * semantics).  We'll destroy this list of buckets the next time
 271              * we are asked to perform a read operation - thus ensuring the
 272              * proper read lifetime.
 273              */
 274             next_list = ctx->list->next;
 275             ctx->list->next = ctx->done;
 276             ctx->done = ctx->list;
 277             ctx->list = next_list;
 278
 279             /* If we have no more in our list, return EOF. */
 280             if (!ctx->list) {
 281                 if (ctx->hold_open) {
 282                     return ctx->hold_open(ctx->hold_open_baton, bucket);
 283                 }
 284                 else {
 285                     return APR_EOF;
 286                 }
 287             }
 288
 289             /* At this point, it safe to read the next bucket - if we can. */
 290
 291             /* If the caller doesn't want ALL_AVAIL, decrement the size
 292              * of the items we just read from the list.
 293              */
 294             if (requested != SERF_READ_ALL_AVAIL) {
 295                 int i;
 296
 297                 for (i = 0; i < cur_vecs_used; i++)
 298                     requested -= vecs[i].iov_len;
 299             }
 300
 301             /* Adjust our vecs to account for what we just read. */
 302             vecs_size -= cur_vecs_used;
 303             vecs += cur_vecs_used;
 304
 305             /* We reached our max.  Oh well. */
 306             if (!requested || !vecs_size) {
 307                 return APR_SUCCESS;
 308             }
 309         }
 310     }
 311
 312     return status;
 313 }
 314
 315 static apr_status_t serf_aggregate_read(serf_bucket_t *bucket,
 316                                         apr_size_t requested,
 317                                         const char **data, apr_size_t *len)
 318 {
 319     aggregate_context_t *ctx = bucket->data;
 320     struct iovec vec;
 321     int vecs_used;
 322     apr_status_t status;
 323
 324     cleanup_aggregate(ctx, bucket->allocator);
 325
 326     status = read_aggregate(bucket, requested, 1, &vec, &vecs_used);
 327
 328     if (!vecs_used) {
 329         *len = 0;
 330     }
 331     else {
 332         *data = vec.iov_base;
 333         *len = vec.iov_len;
 334     }
 335
 336     return status;
 337 }
 338
 339 static apr_status_t serf_aggregate_read_iovec(serf_bucket_t *bucket,
 340                                               apr_size_t requested,
 341                                               int vecs_size,
 342                                               struct iovec *vecs,
 343                                               int *vecs_used)
 344 {
 345     aggregate_context_t *ctx = bucket->data;
 346
 347     cleanup_aggregate(ctx, bucket->allocator);
 348
 349     return read_aggregate(bucket, requested, vecs_size, vecs, vecs_used);
 350 }
 351
 352 static apr_status_t serf_aggregate_readline(serf_bucket_t *bucket,
 353                                             int acceptable, int *found,
 354                                             const char **data, apr_size_t *len)
 355 {
 356     /* Follow pattern from serf_aggregate_read. */
 357     return APR_ENOTIMPL;
 358 }
 359
 360 static apr_status_t serf_aggregate_peek(serf_bucket_t *bucket,
 361                                         const char **data,
 362                                         apr_size_t *len)
 363 {
 364     /* Follow pattern from serf_aggregate_read. */
 365     return APR_ENOTIMPL;
 366 }
 367
 368 static serf_bucket_t * serf_aggregate_read_bucket(
 369     serf_bucket_t *bucket,
 370     const serf_bucket_type_t *type)
 371 {
 372     aggregate_context_t *ctx = bucket->data;
 373     serf_bucket_t *found_bucket;
 374
 375     if (!ctx->list) {
 376         return NULL;
 377     }
 378
 379     if (ctx->list->bucket->type == type) {
 380         /* Got the bucket. Consume it from our list. */
 381         found_bucket = ctx->list->bucket;
 382         ctx->list = ctx->list->next;
 383         return found_bucket;
 384     }
 385
 386     /* Call read_bucket on first one in our list. */
 387     return serf_bucket_read_bucket(ctx->list->bucket, type);
 388 }
 389
 390
 391 const serf_bucket_type_t serf_bucket_type_aggregate = {
 392     "AGGREGATE",
 393     serf_aggregate_read,
 394     serf_aggregate_readline,
 395     serf_aggregate_read_iovec,
 396     serf_default_read_for_sendfile,
 397     serf_aggregate_read_bucket,
 398     serf_aggregate_peek,
 399     serf_aggregate_destroy_and_data,
 400 };